Primary transitional cell carcinoma of the ovary has been only recently recognized, as one of the main types of ovarian carcinoma because of the favorable response to chemotherapy and improved survival of the patient. Histologically, it is distinguished from malignant Brenner tumor only in the absence of benign or proliferative Brenner tumor component. Recent histopathologic reports show that transitional cell carcinoma of the bladder and of the ovary are immunophenotypically different. Primary transitional cell carcinomas are more aggressive than malignant Brenner tumor. However, primary transitional cell carcinomas have a better response to chemotherapy than other types of ovarian carcinomas. We have experienced a very rare case of primary papillary transitional cell carcinoma of the left ovary in a 38-year-old woman and report it with review of literatures.